Ketamine therapy is a newer approach to managing chronic pain. While early results are promising, there’s a lot to consider before giving it a try.
Ketamine therapy is a possible treatment for chronic pain, which is pain that lasts longer than 3 months. While ketamine therapy isn’t typically a first-line treatment, it may be an option if other pain management strategies haven’t worked.
Here’s a closer look at what ketamine therapy for pain management involves, the merging research behind it, and potential risks to consider.
While ketamine therapy is a relatively new concept, ketamine has been used for decades. The Food and Drug Administration (FDA) approved it for medical use in 1970.
The medication acts on N-methyl-D-aspartate (NMDA) receptors in the brain. These receptors operate “channels” that are like switches.
Normally, a neurotransmitter called glutamate switches the NMDA receptor to the “on” position. Glutamate has excitatory effects on the brain and body, meaning it makes you feel more alert and awake.
Ketamine is an antagonist of the NMDA receptor. That means it keeps things like glutamate from activating the NMDA receptor.
When ketamine occupies the receptor, you start to feel sleepy, rather than alert and awake. That’s why ketamine has traditionally been used as an anesthetic.
In addition to the effects mentioned above, experts have uncovered other ketamine effects that suggest it may help with pain management:
- In higher doses, ketamine can work on opioid receptors. Activating these receptors can help reduce pain sensations.
- Ketamine can block some sodium and potassium channels, which is similar to what local anesthetics do.
- Ketamine can help increase the amount of gamma-aminobutyric acid A (GABA) in the brain. GABA is the opposite of glutamate. It causes the brain to experience relaxed, slowed-down sensations.
While experts are still learning about the potential benefits (and downsides) of using ketamine therapy for chronic pain, it may be recommended if other treatments, like opioids or nonsteroidal anti-inflammatory medications, aren’t working.
Ketamine therapy is most commonly used for the following types of pain:
- Neuropathic pain: This refers to pain that affects the nerves, which can cause shooting, tingling, or burning pain.
- Complex regional pain syndrome (CRPS), type I: This pain syndrome most commonly occurs after surgery or injury and causes chronic pain.
Ketamine therapy for chronic pain likely won’t work for every person. Finding the right people who experience unique pain types that respond to ketamine therapy is integral to helping people find pain relief.
Clinics that administer ketamine for chronic pain will usually give the medication via an intravenous line. Usually, treatment begins with a low dose, and clinicians may increase the dose over time.
Ketamine infusion dosages are usually 0.5 to 2 milligrams per kilogram of body weight over the course of 1 hour when administered for chronic pain.
However, ketamine can be given via injection or even inhaled. The options available to you will depend on your location and what your care team thinks will be most beneficial for your symptoms.
Research regarding chronic pain and ketamine is ongoing and still in its early stages.
However, some researchers are putting together reviews of many studies to try and determine whether ketamine may help chronic pain. Here are some results:
- A 2019 systematic review and meta-analysis found intravenous ketamine provided significant pain relief for participants with chronic pain. The effects lasted for about 2 weeks.
- A 2021 review found ketamine may help reduce opioid-induced hyperalgesia. This occurs when opioids have the opposite of their intended effect, making you more sensitive to pain.
- A 2022 study found ketamine administration more effective in relieving chronic pain when given in higher dosages. Researchers followed up with participants after 1 year and found those who experienced mild pain or pain related to fibromyalgia experienced greater, more long lasting pain relief than those with severe pain.
At lower doses, ketamine therapy appears to be safe and well tolerated. Still, ketamine can have a few side effects to be aware of, including:
- increased heart rate
- increased blood pressure
- increased secretions, which could lead to choking
If you have an underlying heart condition, talk with your care team before considering ketamine therapy. These side effects could have a more significant impact on you.
The risk of adverse effects tends to go up when ketamine is used in larger doses or administered frequently.
Ketamine can interact with a range of prescription and over-the-counter medications. In particular, some people who take the medication clarithromycin or who drink grapefruit juice may be more likely to have adverse effects from receiving ketamine. These substances activate certain systems in the body that could make a low dose of ketamine seem like a high one.
Before considering ketamine therapy, it’s important to talk with a healthcare professional about potential interactions with any medications you take.
Ketamine also has the potential to cause physical and psychological dependence, though this risk is low if you follow your healthcare professional’s treatment plan.
Finally, ketamine may cause some people to feel anxious or agitated after administration.
Ketamine therapy is an emerging treatment for chronic pain. If you’re interested in trying it, talk with your care team. Be sure to mention any other treatments you’ve tried, medications you take, and any underlying health conditions.
If you do decide to pursue ketamine therapy, make sure you work with a qualified treatment center that has board certified physicians on staff.